The present invention relates to a resin for use in an antifouling coating to be applied to ships, fishing nets and the like, and to an antifouling coating containing said resin.
An aquatic life, such as barnacles, ascidians, serpulas, Saxidomus bivalves, Bugula bryozoans, green laver and sea lettuce, tends to attach itself to various bodies or structures in the water, causing various kinds of damages. For instance, attachment of such an aquatic life to the hull of a ship will reduce the velocity of the ship, causing an increase in the rate of fuel consumption. When such an aquatic life has attached itself to a fishing net or the like, they may clog meshes of the net and cause death of fish, as is well known.
Therefore, antifouling coatings are used to prevent such an aquatic life from attaching itself to those bodies or structures in the water and growing thereon. As such antifouling coatings, coatings which comprise a polymer having trialkyltin moieties as a vehicle are known. Such antifouling coatings are excellent since the rate of elution of the antifoulant can be controlled at a minimum level necessary for maintaining the antifouling effect and thus the antifoulant can be eluted at a constant rate over a long period of time.
Said antifouling coatings, when applied to ships, for instance, release the tin compound as the result of hydrolysis, in the weakly alkaline milieu of seawater, of the trialkyltin-containing polymer used as vehicle, whereupon the vehicle becomes soluble in water and the coatings are eroded and smoothened. The coatings thus contribute to reducing the resistance due to friction with seawater and reducing the rate of fuel consumption. However, for fear that the trialkyltin compound so eluted should adversely affect the ecosystem, it has been demanded that the development of antifouling coatings which have low toxicity against mammals and thus can be used safely and, at the same time, are capable of insuring the long-sustained antifouling effect.
As compounds meeting such demand, complexes of boron-containing compounds with amines are known.
For example, U. S. Pat. No. 3,211,679 (1965) discloses an antifouling composition for use in seawater which contains, as an active ingredient, not less than 25% by weight of a complex of triphenylborane with a substituted or unsubstituted pyridine of the following general formula (5): 
(wherein R8 represents a hydrogen atom, a halogen atom, a lower alkyl group, an amido group, a cyclic hydrocarbon group or a heterocyclic group), each in meta or para position, or with an aliphatic amine.
Japanese Kokai Publication Sho-39-28579 discloses, as compounds capable of inhibiting growth of microorganisms, complexes of triphenylborane (in which each phenyl group may optionally have a halogen or lower alkoxy substituent in para position), tritolylborane or trinaphthylborane with an amine having a PKb value of not more than 10.
Japanese Kokoku Publication Sho-54-1571 discloses tetraphenylborane complexes represented by the following general formula (6): 
(wherein X represents a potassium atom, an ammonium group, or a quaternized nitrogen-containing group which may be in the form of a nitrogen-containing heterocyclic group).
Japanese Kokoku Publication Sho-62-25710 discloses, as antifoulant compounds, complexes of tetraarylboranes represented by the following general formula (7): 
(wherein R9 represents a hydrogen atom, a halogen atom or a lower alkyl group, R10 represents a halogen atom, a lower alkyl group or a lower alkenyl group and R11 represents a heterocyclic amine), with an ammonium or heterocyclic compound.
Japanese Kokoku Publication Sho-62-24022 discloses, as antifoulant compounds for use in underwater antifouling coatings, tetraphenylborane derivatives represented by the following general formula (8): 
(wherein R12 represents a lower alkyl group).
Japanese Kokai Publication Hei-07-133207 discloses an antifouling composition for fishing nets and implements which comprises triphenylborane-pyridine complex as an essential ingredient.
Japanese Kokai Publication Hei-08-295608 discloses an antifouling composition for fishing nets which comprises one or more triphenylborane-alkylamine complexes represented by the following general formula (9): 
(wherein R13 represents an alkyl group containing 3 to 30 carbon atoms, as active ingredients), and further an organic solvent for dissolving said active ingredients. Japanese Kokai Publication Hei-08-295609, also, discloses an antifouling composition for fishing nets which comprises an organic solvent and a complex of triphenylborane with a primary amine having an n-octadecyl group.
Japanese Kokai Publication Hei-08-295829 discloses an underwater antifouling coating which contains, as an active antifouling ingredient, a complex compound represented by the following general formula (10): 
(wherein R14 is a lower alkyl group, a lower alkoxy group or a halogen atom, n is 1, 2 or 3 and A represents a heterocyclic compound, which may optionally have a substituent or substituents selected from among lower alkyl, carboxyl, aminocarbonyl and so on, or ammonia or an amine compound of the formula R15R16NH (in which R15 and R16 may be the same or different and each independently represents a hydrogen atom, an alkyl group or a cyclohexyl group)).
Japanese Kokai Publication Hei-09-78007 discloses an underwater antifouling coating which contains, as an active ingredient, a triphenylborane-hydroxyalkylamine complex represented by the following general formula (11): 
(wherein X represents a hydroxyalkyl group and n represents an integer of 1 to 3).
However, among the compounds referred to above, the complex of triphenylborane with pyridine or a pyridine derivative is scarcely soluble in organic solvents and, therefore, said complex component is generally contained in the coatings in a suspended state. The problem is that such coatings are difficult to handle since prolonged storage results in precipitation of said complex component.
Other complexes of boron-containing compounds with amine each is a single molecule compound and, therefore, the problem is that even when coatings are formed using a coating which contains the above-mentioned complex compound, it is difficult to control the rate of elution of said complex compound in water, so that the antifouling effect can hardly be maintained for a long period of time.
Japanese Kokai Publication Hei-11-199801 discloses an antifouling coating composition comprising a polymer containing a triarylborane coordinated to N atom as a vehicle. However, this coating composition has drawbacks that the antifouling effect can be maintained for only 3 to 6 months and that the resin itself is insufficiently self-polishing type.
On the other hand, Japanese Kokai Publication Hei-06-25560 discloses the combined use of a heavy metal compound and the copper salt of 2-pyridinethiol-1-oxide for antifouling coatings. This technology is characterized in that the antifouling coatings contain the salt of copper and a fundamental compound having the pyrithione skeleton. However, said technology intends to produce antifouling effects by merely blending such pyrithione skeleton-containing compound with a resin; it does not aim to provide the so-called functional polymer which has the basic feature of controlled hydrolysis and sustained release characteristics.
In view of the prior art mentioned above, the present invention has its object to provide a resin for use in an antifouling coating wherein an eluted antifoulant substance has low toxicity, an antifouling effect is based on a functional polymer having hydrolysis and sustained release characteristics highly controlled and very excellent antifouling effects over a long period of time are obtained, as well as an antifouling coating in which said resin is employed.
The present invention is related to a resin for use in an antifouling coating which comprises a polymer obtained by polymerizing a polymerizable unsaturated monomer(s) and having, at side chain terminals thereof, a trisubstituted borane-amine complex and an azomethine group, or a group represented by the following general formula (1): 
(wherein M represents a metal selected from the group consisting of copper, zinc, nickel and cobalt, --- means a chemically bound state, W represents xe2x80x94N(R1)R2xe2x80x94 (in which R1 and R2 may be the same or different and each represents a hydrogen atom or an alkyl group containing 1 to 4 carbon atoms), xe2x80x94OCOxe2x80x94, xe2x80x94OSO2xe2x80x94 or 
L represents an alkylene group containing 1 to 4 carbon atoms, and m represents an integer of 0 to 4).
In addition, the present invention relates to an antifouling coating comprising the above-mentioned resin for use in an antifouling coating.
In the following, the present invention is described in detail.
The resin for use in an antifouling coating of the present invention is a polymer obtained by polymerizing a polymerizable unsaturated monomer(s) and having, at side chain terminals thereof, a trisubstituted borane-amine complex and an azomethine group, or a group represented by the following general formula (1) given above. Said polymer obtained by polymerizing a polymerizable unsaturated monomer(s) has a characteristic feature of the constitution of the basic polymer of the resin for use in an antifouling coating of the present invention.
Therefore, the xe2x80x9cpolymer obtained by polymerizing a polymerizable unsaturated monomer(s)xe2x80x9d as so referred to herein may be any polymer obtained by polymerizing a polymerizable unsaturated monomer(s) and having a functional group allowing a trisubstituted borane-amine complex and an azomethine group, or a group of the above general formula (1) to be bound thereto and thus includes, without any particular limitations, various polymers, e.g. acrylic polymers, vinyl polymers and polyester polymers, among others. Said expression never restricts the method of producing said polymer but is a notion including, for instance, the case of polymerizing the above-mentioned various monomers with a trisubstituted borane-amine complex and an azomethine group, or a group of general formula (1) bound thereto to give resins for use in an antifouling coating of the present invention, as well.
[1] Cases where the Polymer has a Trisubstituted Borane-amine Complex and an Azomethine Group Bound thereto
In cases where the polymer has a trisubstituted borane-amine complex and an azomethine group bound thereto at side chain terminals thereof, as for the trisubstituted borane-amine complex, the side chain terminals mentioned above generally have an amino group or a substituted or unsubstituted pyridine residue and these form complexes with the trisubstituted borane.
As said amino group, there may be mentioned, for example, groups of the following general formula (4): 
wherein R6 and R7 may be the same or different and each represents a hydrogen atom, an alkyl group, an acyl group or an aryl group).
Said alkyl group is not particularly restricted but includes, among others, methyl, ethyl, n-propyl and i-propyl. Said acyl group is not particularly restricted but includes, among others, formyl, acetyl, propanoyl and propenoyl. Said aryl group includes phenyl, tolyl and so on. R6 and R7 may be the same or different.
The above amino group may be bound to a carbon atom constituting main polymer chain either directly or bound to via an organic group such as an alkylene group or a phenylene group.
As the substituent bound to the above pyridine residue, there may be mentioned an alkyl group, a halogen atom and the like. Generally, such substituent is bound to the 2 or 4 position. Said pyridine residue is generally bound to the main chain or a side chain terminal at the 2 or 4 position thereof.
In addition to those mentioned above, polylysine, chitosan and the like may be mentioned as amino-containing polymers.
Preferred as the trisubstituted borane mentioned above are preferably those represented by the following general formula (3): 
wherein R3, R4 and R5 may be the same or different and each represents an aromatic or aliphatic hydrocarbon group containing 4 to 20 carbon atoms). If the number of carbon atoms in the hydrocarbon group is less than 4, the solubility in organic solvents will be poor, so that it will be difficult to increase the content in the resin. If the number of carbon atoms in the hydrocarbon group exceeds 20, the antifouling effect will become decreased. The number of carbon atoms in each of R3, R4 and R5 is more preferably 4 to 16.
As R3, R4 and R5, there may be mentioned, for example, n-butyl, i-butyl, t-butyl, n-pentyl, i-pentyl, n-hexyl, n-octyl, phenyl, benzyl, phenethyl, tolyl and xylyl. They may be the same or different.
As specific examples of such trisubstituted borane, there may be mentioned di-n-butylphenylborane, diphenyloctylborane, n-butyldiphenylborane, tri-n-butylborane, tri-n-pentylborane, triphenylborane and the like.
Among the trisubstituted boranes mentioned above, those in which two of R3, R4 and R5 are phenyl, for example diphenyloctylborane, are preferred, and triphenylborane in which R3, R4 and R5 each is a phenyl group is more preferred. When two of the substituents are phenyl, it is preferred that the remaining substituent be an alkyl group or an alkenyl group.
The above-mentioned resin for use in an antifouling coating useally has a number average molecular weight of about 400 to 80,000. If the number average molecular weight exceeds 80,000, the resin solution will have a markedly increased viscosity, hence a unnecessarily large amount of solvent will be required and in addition, the controlled release characteristic of the resin will be poor. If, conversely, the number average molecular weight is less than 400, the film-forming properties of the coating will be sacrificed. When the above-mentioned resin for use in an antifouling coating is used for an antifouling coating for fishing net, the number average molecular weight is preferably 500 to 1000 in the viewpoint of more demands for the flexibility of coating films. In the other hand, when the above-mentioned resin for use in an antifouling coating is used for an antifouling coating for ships, the number average molecular weight is preferably 1,500 to 30,000 in the viewpoint of more demands for the film-forming properties of coating films.
The content of the above-mentioned trisubstituted borane-amine complex residue is preferably 0.03 to 0.3 mole per 100 grams of the resulting resin for use in an antifouling coating. If it is less than 0.03 mole per 100 grams, the amount of the trisubstituted borane-containing compound released from the finally formed coating will become decreased, hence the antifouling effects will be insufficient. If it exceeds 0.3 mole per 100 grams, the film-forming properties of the coating will be poor.
The xe2x80x9cpolymer obtained by polymerizing a polymerizable unsaturated monomer(s) and having, at side chain terminals thereof, a trisubstituted borane-amine complex and an azomethine groupxe2x80x9d as so referred to above means only that the polymer finally obtained should have a trisubstituted borane-amine complex and an azomethine group bound to side chain terminals thereof regardless of the time when the amino group or substituted or unsubstituted pyridine residue (hereinafter collectively referred to as amino or like group) is formed and regardless of the time when the trisubstituted borane-amine complex and an azomethine group are formed.
Thus, for example, the polymer containing trisubstituted borane-amine complex may be produced by polymerizing an amino or like group-free polymerizable unsaturated monomer and then introducing an amino or like group into the resulting polymer.
Alternatively, the above-mentioned polymer containing trisubstituted borane-amine complex may be produced by homopolymerizing an amino or like group-containing polymerizable unsaturated monomer or copolymerizing such a monomer with copolymerizable monomer(s) to give a polymer having an amino or like group at a side chain terminal, followed by addition of the trisubstituted borane to said polymer.
Further, the polymer containing trisubstituted borane-amine complex may be produced by first causing addition of the trisubstituted borane to an amino or like group-containing polymerizable unsaturated monomer to give trisubstituted borane adduct-containing monomer and then homopolymerizing the resulting monomer or copolymerizing said trisubstituted borane adduct-containing monomer with copolymerizable monomer(s).
The above-mentioned trisubstituted borane adduct of polymerizable unsaturated monomer can be synthesized by first preparing an amine-trisubstituted borane complex and then subjecting this complex to amine exchange reaction with an amino or like group-containing polymerizable unsaturated monomer. It is also possible to produce said monomer by the method described in Japanese Kokai Publication Sho-62-277307 or Hei-08-311074.
The trisubstituted borane compound such as triphenylborane is generally unstable itself, and the reaction thereof with an amino or like group results in a target polymer with relatively low yield. Therefore, it is preferable to use a trisubstituted borane-base adduct such as sodium hydroxide adduct, or an amine-trisubstituted borane complex prepared beforehand.
As said amino or like group-containing polymerizable unsaturated monomer, there may be mentioned, among others, vinylpyridine, allylamine, vinylamine, aminostyrene and derivatives of these.
The above-mentioned polymerizable unsaturated monomer copolymerizable with such amino or like group-containing polymerizable unsaturated monomer is not particularly restricted but includes, for example, methyl (meth)acrylate, ethyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, polyethylene glycol mono(meth)acrylate and other (meth)acrylate esters; (meth)acrylic acid, (meth)acrylamide, styrene, vinyl acetate, acrylonitrile and the like. These monomers may be used either alone or in combination.
The method of polymerization of the above polymerizable unsaturated monomer(s) is not particularly restricted. Thus, for example, mention may be made of the method which comprises preparing a mixture solution by admixing N-vinylformamide or a like monomer, or such monomer and one or more other polymerizable monomers, with a polymerization initiator and then dropping the mixture dropwise to a solvent such as isopropyl alcohol with heating to thereby effecting the reaction.
According to the present invention, the polymer also has an azomethine group at a side chain terminal thereof. The azomthine group is not particularly limited to the time when it is formed, and may be formed before or after the trisubstituted borane-amine complex is formed. In view of steric hindrance of bulky trisubstituted borane, it is preferable to react with an aldehyde such as benzaldehyde or xcex1-n-amyl cinnamaldehyde, the amino groups or pyridine residues which remain uninvolved in the complex formation with the trisubstituted borane in the resin for use in an antifouling coating, to form the corresponding aldehyde-derived azomethine group.
Such azomethine group formed also produces an antifouling effect and thus increases the antifouling effect of the above-mentioned resin for use in an antifouling coating. The azomethine group is gradually hydrolyzed in water to show antifouling effect, and then, the backbone chain of the resin gradually self-polishes to cause solubilization in water.
The aldehyde is not limited to the kind thereof if a Schiff base can be formed by reacting the aldehyde with the amino or like group. It may be, for example, an aliphatic aldehyde having antimicrobial action such as formaldehyde, glyoxal, succinic aldehyde, glutaric aldehyde and dialdehydes thereof, etc. In the present invention, even an aldehyde having no or weak antimicrobial action is effective because such the aldehyde shows an antifouling effect against attachment of an aquatic life in water. As such the aldehyde, benzaldehyde may typically be mentioned. Also such the aldehyde may be, for example, banzaldehyde derivatives having a substituent on the benzene ring such as p-n-hexylbenzaldehyde, p-octylbanzaldehyde, p-oleylbenzaldehyde, vanilline; aromatic aldehydes such as cinnamaldehyde; and saturated or unsaturated aliphatic aldehydes having not less than 6 carbon atoms such as capronaldehyde, caprylaldehyde, capric aldehyde, laurylaldehyde, stearylaldehyde, oleylaldehyde. In the view of easy manipulation and prolonged antifouling activity, benzaldehyde and the derivatives thereof and saturated or unsaturated aliphatic monoaldehydes having not less than 6 carbon atoms are preferred.
The content of the above-mentioned azomethine group may be 0.01 to 1.5 mole, preferably 0.1 to 1.0 mole, per 100 grams of the resulting resin for use in an antifouling coating.
[2] Cases where the Polymer has a Group of General Formula (1) as Bound thereto
In cases where the polymer mentioned above has a group of the above general formula (1) as bound to side chain terminals thereof, M in general formula (1) represents a metal selected from the group consisting of copper, zinc, nickel and cobalt. - - - means a chemically bound state. W represents xe2x80x94N(R1)R2xe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94OSO2xe2x80x94 or a group of the above formula (2). R1 and R2 may be the same or different and each represents a hydrogen atom or an alkyl group containing 1 to 4 carbon atoms. L represents an alkylene group containing 1 to 4 carbon atoms. m represents an integer of 0 to 4.
Said M is a metal atom directly bound to the S atom constituing pyrithione. Said M may be copper, zinc, nickel or cobalt. Among them, copper and zinc are preferred, however.
Said W is a lower alkyl-substituted or unsubstituted amino group, a carboxyl group, a sulfo group or a pyridino group. Said lower alkyl group is not particularly restricted but includes methyl, ethyl, propyl and butyl, for instance.
In the above general formula (1), - - - means that M and W are in a chemically bound state. By the term xe2x80x9cchemically bound statexe2x80x9d, it is meant that M and W are chemically bound to each other. The chemically bound state is not particularly restricted in kind but includes, for example, covalent bonding, coordination bonding, ionic bonding and complex-forming bonding.
Therefore, in the present specification, the left-end symbol xe2x80x9cxe2x80x94xe2x80x9d appearing in xe2x80x94N(R1)R2xe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94OSO2xe2x80x94 or substituted pyridyl group (formula (2)) as mentioned each as an example of W in the above general formula (1) does not exclusively mean a covalent bond but may vary in the meaning thereof according to the bonding mode of the above-mentioned - - - .
In the above general formula (1), L represents a divalent hydrocarbon group containing 1 to 4 carbon atoms and includes methylene, ethylene and propylene, among others. m represents the number of the L groups, which is an integer of 0 to 4.When m is 0, W is bound directly to a side chain terminal of the polymer.
The number average molecular weight of the above-mentioned resin for use in an antifouling coating is not particularly restricted but may be the same as mentioned above in relation to the cases where the polymer has a trisubstituted borane-amine complex and an azomethine group at side chain terminals thereof.
The above resin for use in an antifouling coating is not particularly restricted only if the condition that a group represented by the above general formula (1) is bound to a side chain terminal of the above polymer. A plurality of side chain terminals may each have such group bound thereto or different groups may be bound.
It is preferred that the above-mentioned group represented by general formula (1) be bound to the polymer in an amount of 0.01 to 0.3 mole per 100 grams of the resulting resin for use in an antifouling coating. If the content of said group is less than 0.01 mole, the amount of the antifoulant substance sustainedly released from the resulting coating will be too small for the effects of the present invention to be produced satisfactorily. If it exceeds 0.3 mole, the film-forming properties of the resulting coating will be reduced.
The polymer having a group of the above general formula (1) bound to side chain terminals thereof can be produced, for example, in the following manner.
An alkali metal salt of pyrithione is used and this is reacted with an inorganic metal salt such as a halide, sulfate or nitrate in water or an alcohol while adequately adjusting the pH, and the reaction product is isolated.
Mention may be made of the method which comprises reacting this isolated product with an organic acid moiety-containing monomer or a mixture of such monomer(s) copolymerizable therewith, to give a polymer, the method which comprises reacting said product isolated with an organic acid moiety-containing polymer to give a polymer, the method which comprises reacting said isolated product with an amine-containing monomer or a mixture of such monomer and one or more monomers copolymerizable therewith, to give a polymer, and the method which comprises reacting said isolated product with an amino-containing polymer to give a polymer, for instance.
Mention may further be made of the method which comprises reacting pyrithione, a low-molecular organic acid metal salt and an organic acid moiety-containing monomer in an appropriate solvent while distilling off the low-molecular organic acid, followed by reaction to give a polymer, a modification of this method which comprises carrying out said method in the presence of a copolymerizable monomer(s) to give a copolymer, the method which comprises reacting pyrithione and a low-molecular organic acid metal salt with an organic acid moiety-containing polymer in an appropriate solvent while distilling off the low-molecular organic acid to give a polymer, the method which comprises reacting an alkali metal salt of pyrithione, an inorganic metal salt and an organic acid-containing monomer in water and, after purification as necessary, further adding a copolymerizable monomer(s), to give a polymer, the method which comprises reacting an alkali metal salt of pyrithione, an inorganic metal salt and an organic acid polymer, and the method which comprises introducing a group of general formula (1) by the organic acid salt exchange reaction, among others.
In the various methods mentioned above, if the monomer is poorly soluble in the organic compound, the methods comprising reacting with a polymer having an appropriate reactive group(s) are preferably employed.
The above-mentioned copolymerizable monomer is not particularly restricted but includes, for example, vinylpyridine, allylamine, vinylamine, aminostyrene, vinylamide, allylamide and like amines and amides and, further, those mentioned hereinabove in relation to the cases where the polymer has a trisubstituted borane-amine complex and an azomethine group bound thereto at side chain terminals thereof.
In the case of the polymer having an amino group or pyridine residue at a side chain terminal thereof, it is preferable to react the amino group or pyridine residue with an aldehyde to form the corresponding aldehyde-derived azomethine group.
[3] Antifouling Coating
The resin for use in an antifouling coating of the present invention can judiciously be used in an antifouling coating, in particular in an antifouling coating to be applied to ship bottoms or fishing nets. An antifouling coating and an antifouling coating for fishing nets, which contains the above-mentioned resin for use in an antifouling coating, each constitutes a subject matter of the present invention.
The antifouling coating of the present invention is obtained by adding, to the above resin for use in an antifouling coating, additives in common use, such as additives include antifoulants, plasticizers, coating erosion modifiers, pigments, solvents and so on.
The above-mentioned antifoulants are not particularly restricted but any of those known in the art can be used. As examples, there may be mentioned metals in powder or flake form, such as copper, zinc and nickel; oxides, hydroxides and halides of metals such as copper and zinc; copper suboxide, copper rhodanide and other metal salts; carboxylic acid metal salts such as copper naphthenate and metal stearates; metal dithio-carbamates such as zinc dimethyldithiocarbamate, bisdimethyldithiocarbamoylzinc and ethylenebisdithiocarbamates; thiuram disulfides such as tetramethylthiuram disulfide; sulfamides such as phthalylsulfathiazole, sulfaethidole, sulfanilidopyridine, sulfamethoxine and N,Nxe2x80x2-dimethyl-Nxe2x80x2-phenyl-N-fluorodichloromethylthiosulfamide; pyrrols and imidazoles such as glyodin, phentizole, and polycide; thioxanes and thioxanthones such as terrazole, asterol and mylone; imides and amides such as nicarbazin, 3,4,5-tribromosalicylanilide, N-trichloromethylmercaptophthalimide, 3,5-dinitrobenzamide, 2,4,6-trichlorophenylmaleimide and N-fluorodichloromethylthiophthalimide; sulfur-containing organic compounds and halogen-containing organic compounds such as 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine, 2,4,5,6-tetrachlorophthalonitrile, N,Nxe2x80x2-dimethyldichlorophenylurea, 4,5-dichloro-2-n-octyl-3(2H)-isothiazoline, 2-pyridinethio-1-oxide zinc salt, 2-pyridinethiol-1-oxide copper salt, 2,3,5,6-tetrachloro-4-methylsulfonylpyridine, 3-iodo-2-propyl butylcarbamate and diuodomethyl paratolyl sulfone; pyridine-triphenylborane, alkylpyridine-triphnylborane, alkylamine-triphenylborane such as stearylamine-triphenylborane, and other agrochemicals, medicinals, microbicides and the like.
Said plasticizers are not particularly restricted but include, among others, phthalate ester plasticizers such as dioctyl phthalate, dimethyl phthalate and dicyclohexyl phthalate; aliphatic dibasic acid ester plasticizers such as diisobutyl adipate and dibutyl sebacate; glycol ester plasticizers such as diethylene glycol dibenzoate and pentaerythritol alkyl esters; phosphate ester plasticizers such as tricresyl phosphate and trichloroethyl phosphate; epoxy plasticizers such as epoxidized soybean oil and octyl epoxystearate; organotin plasticizers such as dioctyltin laurate and dibutyltin laurate; trioctyl trimellitate, triacetylene and the like.
Said coating erosion modifiers are not particularly restricted but include, among others, chlorinated paraffin, polyvinyl ethers, polypropylene sebacate, partially hydrogenated terphenyl, polyvinyl acetate, alkyl (meth) acrylate polymers, polyether polyols, alkyd resins, polyester resins, polyvinyl chloride, silicone oils, waxes, vaseline, liquid paraffin and the like.
Said pigments are not particularly restricted but include, among others, extenders such as precipitated barium sulfate, talc, clay, chalk, silica white, alumina white and bentonite; color pigments such as titanium oxide, zirconium oxide, basic lead sulfate, tin oxide, carbon black, graphite, iron oxide red, chrome yellow, phthalocyanine green, phthalocyanine blue and quinacridones; and the like.
Said solvents are not particularly restricted but include, among others, hydrocarbons such as toluene, xylene, ethylbenzene, cyclopentane, octane, heptane, cyclohexane and white spirits; ethers such as dioxane, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether and diethylene glycol monoethyl ether; esters such as butyl acetate, propyl acetate, benzyl acetate, ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; ketones such as ethyl isobutyl ketone and methyl isobutyl ketone; alcohols such as n-butanol and propyl alcohol; and the like.
Other additives than those mentioned above are not particularly restricted but include, among others, rosins, monobutyl phthalate, monooctyl succinate and like organic monobasic acids, camphor, castor oil and the like.
The above antifouling coating can be prepared by adding such additives in common use such as antifoulants, plasticizers, coating erosion modifiers, pigments, solvents and so forth to the above resin for use in an antifouling coating, followed by blending using a mixing machine such as a ball mill, pebble mill, roll mill or sand grind mill.
As mentioned above, the antifouling coating of the present invention contains the above-mentioned resin for use in an antifouling coating and, when used as an antifouling coating for ships, fishing nets, marine structures and the like, can form very excellent antifouling coatings which can gradually release the trisubstituted borane-containing compound and the compound resulting from the azomethine group, or the compound resulting from the group of general formula (1) from the coating films and thereby can maintain the antifouling effects over a long period of time. In particular when the polymer has a trisubstituted borane-amine complex and an azomethine group bound thereto at side chain terminals thereof, the elution of the trisubstituted borane-amine complex and the compound resulting from the azomethine group from the antifouling coatings can be controlled by adequately selecting the resin species for use in an antifouling coating, the side chain length and species of the trisubstituted borane-amine complex and the azomethine group bound at side chain terminals, among others.
When applied to ships and the like, the antifouling coating of the present invention can produce its excellent antifouling effects, inhibiting the attachment and/or growth of aquatic lives, such as barnacles, ascidians, serpulas, Saxidomus bivalves, fresh-water mussels and Bugula bryozoans, over a prolonged period of time.
When applied to fishing nets, said composition can prevent the attachment and/or growth of such an aquatic life as mentioned above over a long period of time and, in particular, it can effectively inhibit the attachment of seaweeds such as green laver and sea lettuce.
Thus, the antifouling coating of the present invention can suitably be applied to ships such as tankers, ferries, fishing boats, steel-clad ships, wooden vessels and FRP boats; marine structures, fishing nets for culture, fishing nets such as fixed shore nets or like, water conveyance ducts, fishing implements and so forth.